Pump system

ABSTRACT

Aspects of the disclosure relate to pumping systems, apparatus, end related methods for longer strong lengths and reduced footprints. In one aspect, pumping systems facilitate increased horsepower generated at lower cycle rates and a lesser number of pumps. In one implementation, a pump system comprises a hydraulic power end coupled to and located in between a first fluid end and a second fluid end. The hydraulic power end comprises a hydraulic cylinder assembly having a piston, a first rod coupled to the piston and to the first fluid end, and a second rod coupled to the piston and to the second fluid end located on the opposite side.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent applicationSer. No. 63/143,580, filed Jan. 29, 2021, which is herein incorporatedby reference in its entirety

BACKGROUND Field

Aspects of the disclosure relate to pump systems for pumping fluid intoan oil and gas well.

Description of the Related Art

Pump systems, such as frac pumps, are frequently used in oil and gasoperations to pump fluids at high pressures into an oil and gas well.Due to the high pressures, volumes, and flow rates of fluids that arecirculated through the pump systems, numerous resources are needed tomaintain the operating efficiency of the pump systems, which increasesthe overall costs of such oil and gas operations. In addition, the powerrequirements and the physical space needed to operate the pump systemsat an oil and gas site significantly increases as drilling technologyenables more and more oil and gas wells to be drilled at the same site,which similarly increases the overall costs of such oil and gasoperations.

Therefore, there is a continuous need for new and improved pump systems.

SUMMARY

Aspects of the disclosure relate to pumping systems, apparatus, endrelated methods for longer strong lengths and reduced footprints. In oneaspect, pumping systems facilitate increased horsepower generated atlower cycle rates and a lesser number of pumps.

In one implementation, a pump system comprises a hydraulic power endcomprising a hydraulic cylinder having a hydraulic cylinder housing, anda cylinder rod assembly disposed at least partially in the hydrauliccylinder housing, the cylinder rod assembly comprising: a pistondisposed in the hydraulic cylinder housing, a first rod coupled to thepiston and extending from a first end of the piston and out of a firstside of the hydraulic cylinder, and a second rod coupled to the pistonand extending from a second end of the piston and out of a second sideof the hydraulic cylinder; and a first fluid end comprising a firstfluid end block disposed adjacent the first side of the hydrauliccylinder; and a second fluid end comprising a second fluid end blockdisposed adjacent the second side of the hydraulic cylinder.

In one implementation, a pump system comprises a hydraulic power endcomprising a hydraulic cylinder having a hydraulic cylinder housing, anda cylinder rod assembly disposed at least partially in the hydrauliccylinder housing, the cylinder rod assembly comprising a piston disposedin a piston chamber of the hydraulic cylinder housing, and a hydraulicfluid circuit comprising: a first supply line coupled to the pistonchamber of the hydraulic cylinder housing on a first side of the piston,a first return line coupled to the piston chamber of the hydrauliccylinder housing on the first side of the piston, a second supply linecoupled to the piston chamber of the hydraulic cylinder housing on asecond side of the piston, a second return line coupled to the pistonchamber of the hydraulic cylinder housing on the second side of thepiston, and one or more pumps coupled to supply a hydraulic fluid to thefirst supply line and the second supply line; and a fluid end comprisinga fluid end block that receives an end of the cylinder rod assembly.

In one implementation, a pump system comprises a hydraulic power endcomprising a hydraulic cylinder having a hydraulic cylinder housing, anda cylinder rod assembly disposed at least partially in the hydrauliccylinder housing, the cylinder rod assembly comprising: a pistondisposed in the hydraulic cylinder housing, and a rod section coupled tothe piston and extending from the piston and out of a first side of thehydraulic cylinder, wherein a first end of the rod section is coupled tothe piston; and a fluid end comprising a fluid end block, wherein asecond end of the rod section is received in the fluid end block.

In one implementation, a method of operating a pump system comprisessupplying pressurized fluid via a first supply line into a pistonchamber on a first side of a piston of a cylinder rod assembly;exhausting pressurized fluid via a second return line from the pistonchamber on a second side of the piston, wherein supplying and exhaustingthe pressurized fluid pressurizes the first side of the piston relativeto the second side of the piston to move the piston and the cylinder rodassembly in a first direction toward a first fluid end; and thensupplying pressurized fluid via a second supply line into the pistonchamber on the second side of the piston; exhausting pressurized fluidvia a first return line from the piston chamber on the first side of thepiston, wherein supplying and exhausting of pressurized fluidpressurizes the second side of the piston relative to the first side ofthe piston to move the piston and the cylinder rod assembly in a seconddirection toward a second fluid end, the second direction is opposite ofthe first direction.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the disclosurecan be understood in detail, a more particular description of thedisclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a schematic partial sectional view of a pump system, accordingto one implementation.

FIG. 2 is a schematic diagram view of a method of operating a pumpsystem, according to one implementation

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneimplementation may be beneficially utilized on other implementationswithout specific recitation.

DETAILED DESCRIPTION

Aspects of the disclosure relate to pumping systems, apparatus, endrelated methods for longer strong lengths and reduced footprints. In oneaspect, pumping systems facilitate increased horsepower generated atlower cycle rates and a lesser number of pumps.

The disclosure contemplates that terms such as “couples,” “coupling,”“couple,” and “coupled” may include but are not limited to welding,interference fitting, and/or fastening such as by using bolts, threadedconnections, pins, and/or screws. The disclosure contemplates that termssuch as “couples,” “coupling,” “couple,” and “coupled” may include butare not limited to integrally forming. The disclosure contemplates thatterms such as “couples,” “coupling,” “couple,” and “coupled” may includebut are not limited to direct coupling and/or indirect coupling. Thedisclosure contemplates that terms such as “couples,” “coupling,”“couple,” and “coupled” may include operable coupling such as electriccoupling and/or fluidly coupling.

FIG. 1 is a schematic partial sectional view of a pump system 100,according to one implementation. In one embodiment, which can becombined with other embodiments, the pump system 100 is a frac or mudpump system. The pump system 100 can be transported and deployed on atruck at an oil and gas wellhead site.

The pump system 100 includes a hydraulic power end 105. The hydraulicpower end 105 includes a hydraulic cylinder 104 having a hydrauliccylinder housing 106, and a cylinder rod assembly 107 disposed in apiston chamber 108 of the hydraulic cylinder housing 106. The cylinderrod assembly 107 includes a piston 109 disposed in the piston chamber108 of the hydraulic cylinder housing 106, a first rod 110 coupled tothe piston 109 and extending from a first end of the piston 109 and outof a first side 112 of the hydraulic cylinder 104, and a second rod 111coupled to the piston 109 and extending from a second end of the piston109 and out of a second side 113 of the hydraulic cylinder 104. The pumpsystem 100 includes a first fluid end 115A having a first fluid endblock 116A disposed on and adjacent to the first side 112 of thehydraulic cylinder 104. The first fluid end block 116A includes adischarge outlet 117A having a check valve 118A disposed therein, and asuction inlet 119A having a check valve 120A disposed therein.

The pump system 100 includes a second fluid end 115B having a secondfluid end block 116B disposed on and adjacent to the second side 113 ofthe hydraulic cylinder 104. The second fluid end block 116B includes adischarge outlet 117B having a check valve 118B disposed therein, and asuction inlet 119B having a check valve 120B disposed therein. Thepiston 109, the first rod 110, and the second rod 111 are part of aplunger that is received in the first fluid end block 116A and thesecond fluid end block 116B. The cylinder rod assembly 107 functions asthe plunger. The cylinder rod assembly 107 reciprocates in a firstdirection D1 toward the first fluid end block 116A and a seconddirection D2 toward the second fluid end block 116B. As the cylinder rodassembly 107 moves in the first direction D1, an operation fluid F1 ispumped from the suction inlet 119A and out through the discharge outlet117A. As the cylinder rod assembly 107 moves in the second direction D2,the operation fluid F1 is pumped from the suction inlet 119B and outthrough the discharge outlet 117B. The operation fluid F1 is a fracfluid that is pumped into one or more wellheads.

The hydraulic cylinder 104, is a double-acting hydraulic cylinder, thepiston 109 is a double-acting piston, and the cylinder rod assembly 107is a double-acting reciprocating plunger that can pump in two directionssuch that a forward stroke pumps an operation fluid and a return strokealso pumps an operation fluid. The pump system 100 is a hydraulicintensifier frac pump.

The piston 109 of the cylinder rod assembly 107 is coupled to a firstend 121 of the first rod 110 and a first end 123 of the second rod 111.The piston 109 functions as a sealed cap coupled to and disposed aboutthe first end 121 and the first end 123 to enclose and seal the firstend 121 and the first end 123. A second end 122 of the first rod 110 isreceived in the first fluid end block 116A. A second end 124 of thesecond rod 111 is received in the second fluid end block 116B. Each ofthe first rod 110 and the second rod 111 is hollow and has a respectiveinner bore 125, 126. The cylinder rod assembly 107 includes a cap 127disposed adjacent the second end 122 and coupled to the first rod 110,such as by using a bolt. In one embodiment, which can be combined withother embodiments, a portion of the cap 127 extends into the inner bore125 of the first rod 110. The cylinder rod assembly 107 includes a cap128 disposed adjacent the second end 124 and coupled to the second rod111, such as by using a bolt. In one embodiment, which can be combinedwith other embodiments, a portion of the cap 128 extends into the innerbore 126 of the second rod 111. The present disclosure contemplates thatthe first rod 110 and the second rod 111 can be integrally formed as asingle rod that extends through the piston 109 and is coupled to thepiston 109.

The hydraulic cylinder 104 includes a first cylinder cap 130 disposed atthe first side 112 and coupled to the hydraulic cylinder housing 106 anda second cylinder cap 140 disposed at the second side 113 and coupled tothe hydraulic cylinder housing 106. The pump system 100 includes a firstpacking housing 180 and a first plurality of packing seals 181 disposedbetween the first fluid end block 116A and the first cylinder cap 130.The first packing housing 180 and the first plurality of packing seals181 are disposed about the first rod 110. The pump system 100 includes asecond packing housing 182 and a second plurality of packing seals 183disposed between the second fluid end block 116B and the second cylindercap 140. The second packing housing 182 and the second plurality ofpacking seals 183 are disposed about the second rod 111.

A first fluid end spool 184A is coupled between the first packinghousing 180 and the first fluid end block 116A. A second fluid end spool1846 is coupled between the second packing housing 182 and the secondfluid end block 116B. The respective fluid end spools 184A, 184Bfacilitating spacing the respective fluid ends 115A, 115B from therespective packing housings 180, 182 and the hydraulic cylinder 104. Therespective fluid end spools 184A, 1846 also facilitate protecting therespective rods 110, 111.

The pump system 100 includes a hydraulic fluid circuit 150 coupled to(e.g. in fluid communication with) the hydraulic cylinder 104 of thepump system 100. The hydraulic fluid circuit 150 includes a first supplyline 131 coupled to the piston chamber 108 of the hydraulic cylinderhousing 106 on a first side 132 of the piston 109, and a first returnline 133 coupled to the piston chamber 108 of the hydraulic cylinderhousing 106 on the first side 132 of the piston 109. The hydraulic fluidcircuit 150 includes a second supply line 141 coupled to the pistonchamber 108 of the hydraulic cylinder housing 106 on a second side 142of the piston 109, and a second return line 143 coupled to the pistonchamber 108 of the hydraulic cylinder housing 106 on the second side 142of the piston 109. The first supply line 131 supplies hydraulic fluid H1to the piston chamber 108 on the first side 132 of the piston 109, andthe first return line 133 exhausts the hydraulic fluid H1 out of thepiston chamber 108 on the first side 132. The second supply line 141supplies hydraulic fluid H2 to the piston chamber 108 on the second side142 of the piston 109, and the second return line 143 exhausts thehydraulic fluid H2 out of the piston chamber on the second side 142.

The hydraulic fluid circuit 150 includes one or more reservoirs 151 (onereservoir 151 is shown) to receive the hydraulic fluid H1 from the firstreturn line 133 and the hydraulic fluid H2 from the second return line143. The reservoirs 151 include tanks and/or bladders. The hydraulicfluid circuit 150 includes one or more pumps (a first pump 152 and asecond pump 153 are shown). The first pump 152 is coupled to supply thehydraulic fluid H1 to the first supply line 131, and the second pump 153is coupled to supply the hydraulic fluid H2 to the second supply line141. Each of the first pump 152 and the second pump 153 is a 1,000horsepower pump such that the hydraulic cylinder 104 generates 2,000horsepower in output. In one embodiment, which can be combined withother embodiments, each of the first pump 152 and the second pump 153 isan axial piston variable pump.

The hydraulic fluid circuit 150 includes a first supply valve 136 alongthe first supply line 131 that, when open, supplies the hydraulic fluidH1 to the piston chamber 108 on the first side 132 of the piston 109.The first supply valve 136 is disposed in the first cylinder cap 130 andwithin the hydraulic cylinder housing 106 of the hydraulic cylinder 104.Specifically, the first supply valve 136 is shown disposed in a fluidport 134 formed in the first cylinder cap 130 but can be positionedanywhere along the first supply line 131. The hydraulic fluid circuit150 includes a first return valve 137 along the first return line 133that, when open, returns the hydraulic fluid H1 from the piston chamber108 on the first side 132 of the piston 109 to the one or morereservoirs 151. The first return valve 137 is disposed in the firstcylinder cap 130 and within the hydraulic cylinder housing 106 of thehydraulic cylinder 104. Specifically, the first return valve 137 isshown disposed in a fluid port 135 formed in the first cylinder cap 130but can be positioned anywhere along the first return line 133.

The hydraulic fluid circuit 150 includes a second supply valve 146 alongthe second supply line 141 that, when open, supplies the hydraulic fluidH2 to the piston chamber 108 on the second side 142 of the piston 109.The second supply valve 146 is disposed in the second cylinder cap 140and within the hydraulic cylinder housing 106 of the hydraulic cylinder104. Specifically, the second supply valve 146 is shown disposed in afluid port 144 formed in the second cylinder cap 140 but can bepositioned anywhere along the second supply line 141. The hydraulicfluid circuit 150 includes a second return valve 147 along the secondreturn line 143 that, when open, returns the hydraulic fluid H2 from thepiston chamber 108 on the second side 142 of the piston 109 the one ormore reservoirs 151. The second return valve 147 is disposed in thesecond cylinder cap 140 and within the hydraulic cylinder housing 106 ofthe hydraulic cylinder 104. Specifically, the second return valve 147 isshown disposed in a fluid port 145 formed in the second cylinder cap 130but can be positioned anywhere along the second return line 143.

In one embodiment, which can be combined with other embodiments, each ofthe first supply valve 136, the first return valve 137, the secondsupply valve 146, and the second return valve 147 is a pressure controlvalve (PCV). In one embodiment, which can be combined with otherembodiments, each of the first supply valve 136, the first return valve137, the second supply valve 146, and the second return valve 147 is agate valve, a ball valve, a swing valve, and/or any other type ofisolation valve (e.g. an on/off valve).

The first supply line 131 and the first return line 133 are disposed onthe first side 132 of the piston 109. The second supply line 141 and thesecond return line 143 are disposed on the second side 142 of the piston109. The first fluid end block 116A is disposed at a first distance L1relative to an outer end of the first cylinder cap 130. The second fluidend block 1166 is disposed at a second distance L2 relative to an outerend of the second cylinder cap 140. In one embodiment, which can becombined with other embodiments, each of the first distance L1 and thesecond distance L2 is within a range of 32 inches to 52 inches, such as52 inches or less.

The pump system 100 includes a controller 160 coupled to the hydraulicfluid circuit 150. The controller 160 is configured to controloperations of the one or more pumps 152, 153, the first supply valve136, the second supply valve 146, the first return valve 137, and thesecond return valve 147. The controller 160 is configured to open thefirst supply valve 136 (thereby supplying the hydraulic fluid H1 to thepiston chamber 108 on the first side 132 of the piston 109) and open thesecond return valve 147 (thereby exhausting the hydraulic fluid H2 fromthe piston chamber 108 on the second side 142 of the piston 109), whileclosing the second supply valve 146 and the first return valve 137 tomove the piston 109 in the first direction D1 toward the first fluid endblock 116A. The first pump 152 is powered while the first supply valve136 is open and the first return valve 137 is closed to pump thehydraulic fluid H1 through the first supply line 131 and through thefirst supply valve 136. The second pump 153 is powered while the secondreturn valve 147 is open and the second supply valve 146 is closed toreturn the hydraulic fluid H2 through the second return valve 147 andthrough the second return line 143.

The controller 160 is configured to open the second supply valve 146(thereby supplying the hydraulic fluid H2 to the piston chamber 108 onthe second side 142 of the piston 109) and open the first return valve137 (thereby exhausting the hydraulic fluid H1 from the piston chamber108 on the first side 132 of the piston 109), while closing the firstsupply valve 136 and the second return valve 147 to move the piston 109in the second direction D2 that is opposite of the first direction D1.The second pump 153 is powered while the second supply valve 146 is opento pump the hydraulic fluid H2 through the second supply line 141 andthrough the second supply valve 146. The first pump 152 is powered whilethe first return valve 137 is open and the first supply valve 136 isclosed to return the hydraulic fluid H1 through the first return valve137 and through the first return line 133.

Moving the piston 109 in the first direction D1 moves the first rod 110in the first direction D1 to pump the operation fluid F1 from thesuction inlet 119A and out through the discharge outlet 117A of thefirst fluid end block 116A. Moving the piston 109 in the seconddirection D2 moves the second rod 111 in the second direction D2 to pumpthe operation fluid F1 from the suction inlet 1196 and out through thedischarge outlet 1176 of the second fluid end block 1166.

The present disclosure contemplates that one or more additionalreservoirs 151 and/or one or more additional pumps 152, 153 may be used.In one embodiment, which can be combined with other embodiments, thefirst pump 152 is coupled to the first supply line 131 to supply thehydraulic fluid H1, a first reservoir 151 is coupled to the first returnline 133 to return the hydraulic fluid H1, the second pump 153 iscoupled to the second supply line 141 to supply the hydraulic fluid H2,and a second reservoir 151 is coupled to the second return line 143 toreturn the hydraulic fluid H2. In one example, which can be combinedwith other examples, the first supply line 131 is fluid separated fromthe second supply line 141, and the first return line 133 is fluidlyseparated from the second return line 143. The present disclosurecontemplates that the first supply line 131 and the second supply line141 may be fluidly connected such that the same hydraulic fluid can besupplied from the one or more reservoirs 151 and split to be thehydraulic fluid H1 and the hydraulic fluid H2. The present disclosurecontemplates that the first return line 133 and the second return line143 may be fluidly connected such that the hydraulic fluid H1 and thehydraulic fluid H2 merge together prior to returning to the one or morereservoirs 151.

The first supply valve 136, the first return valve 137, the secondsupply valve 146, and the second return valve 147 may be directionalcontrol valves. As described herein, the the first supply valve 136 canbe disposed anywhere along the first supply line 131, the first returnvalve 137 can be disposed anywhere along the first return line 133, thesecond supply valve 146 can be disposed anywhere along the second supplyline 141, and the second return valve 147 can be disposed anywhere alongthe second return line 143. In one embodiment, which can be combinedwith other embodiments, the first supply valve 136 is disposed withinthe first pump 152 to control fluid flow along the first supply line 131from the one or more reservoirs 151 to the piston chamber 108, and thefirst return valve 137 is disposed within the first pump 152 to controlfluid flow along the first return line 133 from the piston chamber 108to the one or more reservoirs 151. In one embodiment, which can becombined with other embodiments, the second supply valve 146 is disposedwithin the second pump 153 to control fluid flow along the second supplyline 141 from the one or more reservoirs 151 to the piston chamber 108,and the second return valve 147 is disposed within the second pump 153to control fluid flow along the second return line 143 from the pistonchamber 108 to the one or more reservoirs 151.

The present disclosure contemplates that a cooling system may be used tocool components of the hydraulic power end 105 and/or cool components ofthe hydraulic fluid circuit 150.

The present disclosure contemplates that existing pump systems (such asfrac or mud pump systems) can be retrofitted, according to retrofittingmethods, to include aspects, features, components, and/or properties ofthe pump system 100. Existing pump systems can be retrofitted, usingaspects described herein, without replacing the existing packing housingor the existing fluid end block.

The hydraulic power end 105, the first fluid end 115A, and the secondfluid and 115B are disposed in a linear arrangement. The hydraulic powerend 105 need not use gears (such as a transmission system) or acrankshaft therein.

FIG. 2 is a schematic diagram view of a method 200 of operating a pumpsystem, according to one implementation. The controller 160 describedabove can be configured to carry out the operations 202, 204, 206, 208,210, and 212 of the method 200 described below. Operation 202 includessupplying pressurized fluid via a first supply line (such as through afirst supply valve) into a piston chamber on a first side of a piston ofa cylinder rod assembly. Operation 204 includes exhausting pressurizedfluid via a second return line (such as through a second return valve)from the piston chamber on a second side of the piston. The supplying ofoperation 202 and the exhausting of operation 204 facilitatespressurizing the first side of the piston relative to the second side ofthe piston. Operation 206 includes moving the piston and the cylinderrod assembly in a first direction toward a first fluid end.

Operation 208 of the method 200 includes supplying pressurized fluid viaa second supply line (such as through a second supply valve) into thepiston chamber on the second side of the piston. Operation 210 includesexhausting pressurized fluid via a first return line (such as through afirst return valve) from the piston chamber on the first side of thepiston. The supplying of operation 208 and the exhausting of operation210 facilitates pressurizing the second side of the piston relative tothe first side of the piston. Operation 212 includes moving the pistonand the cylinder rod assembly in a second direction toward a secondfluid end. The second direction is opposite of the first direction. Themovement of the cylinder rod assembly in the second directionreciprocates the cylinder rod assembly.

Benefits of the present disclosure include a shortened length and ashortened footprint for pump units, such as those transported anddeployed on truck trailers, relative to other pump units. As an example,aspects of the present disclosure facilitate a length reduction of about40%. Benefits of the present disclosure also include facilitating alower stroke cycle rate (for example, less than 100 cycles per minute,such as about 40 cycles per minute) at the same horsepower or a largerhorsepower relative to other pumps (such as frac pumps that can operateat 150 cycles per minute to generate a required power output). Loweringstroke cycle rates facilitate increased lifespan, decreased downtime,reliable power generation, increased efficiency, and reduced costs andmaintenance.

Benefits of the present disclosure also include increased horsepower atthe same footprint relative to frac pumps. Benefits of the presentdisclosure also facilitate using a lower number of hydraulic cylindersand a lower number of frac trucks deployed to achieve a horsepoweroutput. As an example, a single hydraulic cylinder using aspectsdescribed herein can generate 2,000 horsepower relative to otherhydraulic cylinders that generate 1,000 horsepower, and a single fractruck using aspects described herein can generate 12,000 horsepowerrelative to other frac trucks that generate 6,000 horsepower. As anexample, a frac operation at a wellhead site using operations describedherein can deploy 3 frac trucks relative to other frac operations thatmay use 16 or more frac trucks.

Benefits of the present disclosure also include ease of disassembly forease of maintenance. As an example, the first rod 110 and/or the secondrod 111 can be decoupled from the piston 109 and removed from thehydraulic cylinder housing 106 without needing to first remove therespective fluid end block 116A, 116B from the respective rod 110, 111.

It is contemplated that one or more of the aspects disclosed herein maybe combined. Moreover, it is contemplated that one or more of theseaspects may include some or all of the aforementioned benefits. As anexample, aspects, features, components, and/or properties of the pumpsystem 100 can be combined with the method 200.

It will be appreciated by those skilled in the art that the precedingembodiments are exemplary and not limiting. It is intended that allmodifications, permutations, enhancements, equivalents, and improvementsthereto that are apparent to those skilled in the art upon a reading ofthe specification and a study of the drawings are included within thescope of the disclosure. It is therefore intended that the followingappended claims may include all such modifications, permutations,enhancements, equivalents, and improvements. The disclosure alsocontemplates that one or more aspects of the embodiments describedherein may be substituted in for one or more of the other aspectsdescribed. The scope of the disclosure is determined by the claims thatfollow.

I claim:
 1. A pump system, comprising: a hydraulic power end comprisinga hydraulic cylinder having a hydraulic cylinder housing, and a cylinderrod assembly disposed at least partially in the hydraulic cylinderhousing, the cylinder rod assembly comprising: a piston disposed in thehydraulic cylinder housing, a first rod coupled to the piston andextending from a first end of the piston and out of a first side of thehydraulic cylinder, and a second rod coupled to the piston and extendingfrom a second end of the piston and out of a second side of thehydraulic cylinder; and a first fluid end comprising a first fluid endblock disposed adjacent the first side of the hydraulic cylinder; and asecond fluid end comprising a second fluid end block disposed adjacentthe second side of the hydraulic cylinder.
 2. The pump system of claim1, wherein the piston of the cylinder rod assembly is coupled to a firstend of the first rod and a first end of the second rod.
 3. The pumpsystem of claim 2, wherein the first fluid end block receives a secondend of the first rod of the cylinder rod assembly.
 4. The pump system ofclaim 3, wherein the second fluid end block receives a second end of thesecond rod of the cylinder rod assembly.
 5. The pump system of claim 4,wherein each of the first rod and the second rod of the cylinder rodassembly is hollow.
 6. A pump system, comprising: a hydraulic power endcomprising a hydraulic cylinder having a hydraulic cylinder housing, anda cylinder rod assembly disposed at least partially in the hydrauliccylinder housing, the cylinder rod assembly comprising a piston disposedin a piston chamber of the hydraulic cylinder housing; a hydraulic fluidcircuit comprising: a first supply line coupled to the piston chamber ofthe hydraulic cylinder housing on a first side of the piston, a firstreturn line coupled to the piston chamber of the hydraulic cylinderhousing on the first side of the piston, a second supply line coupled tothe piston chamber of the hydraulic cylinder housing on a second side ofthe piston, a second return line coupled to the piston chamber of thehydraulic cylinder housing on the second side of the piston, and one ormore pumps coupled to supply a hydraulic fluid to the first supply lineand the second supply line; a first fluid end that receives a first endof the cylinder rod assembly; and a second fluid end that receives asecond end of the cylinder rod assembly.
 7. The pump system of claim 6,wherein the hydraulic fluid circuit further comprises one or morereservoirs to receive the hydraulic fluid from the first return line andthe second return line.
 8. The pump system of claim 7, wherein thehydraulic fluid circuit further comprises: a first supply valve alongthe first supply line that, when open, supplies the hydraulic fluid tothe piston chamber on the first side of the piston; and a second supplyvalve along the second supply line that, when open, supplies thehydraulic fluid to the piston chamber on the second side of the piston.9. The pump system of claim 8, wherein the hydraulic fluid circuitfurther comprises: a first return valve along the first return linethat, when open, returns the hydraulic fluid from the piston chamber onthe first side of the piston to the one or more reservoirs; and a secondreturn valve along the second return line that, when open, returns thehydraulic fluid from the piston chamber on the second side of the pistonto the one or more reservoirs.
 10. The pump system of claim 9, whereineach of the first supply valve, the second supply valve, the firstreturn valve, and the second return valve is disposed within thehydraulic cylinder.
 11. The pump system of claim 9, further comprising acontroller coupled to each of the one or more pumps, the first supplyvalve, the second supply valve, the first return valve, and the secondreturn valve.
 12. The pump system of claim 11, wherein the controller isconfigured to open the first supply valve and the second return valvewhile the second supply valve and the first return valve are closed tomove the piston in a first direction toward the fluid end block.
 13. Thepump system of claim 12, wherein the controller is further configured toopen the second supply valve and the first return valve while the firstsupply valve and the second return valve are closed to move the pistonin a second direction that is opposite of the first direction.
 14. Thepump system of claim 6, wherein the first end of the cylinder rodassembly comprises a first rod coupled to the piston and extending fromthe first side of the piston and out of a first side of the hydrauliccylinder housing, wherein the second end of the cylinder rod assemblycomprises a second rod coupled to the piston and extending from thesecond side of the piston and out of a second side of the hydrauliccylinder housing, wherein the first fluid end receives the first rodthat extends out of the hydraulic cylinder housing, and wherein thesecond fluid end receives the second rod that extends out of thehydraulic cylinder housing.
 15. A method of operating a pump system,comprising: supplying pressurized fluid via a first supply line into apiston chamber on a first side of a piston of a cylinder rod assembly;exhausting pressurized fluid via a second return line from the pistonchamber on a second side of the piston, wherein supplying and exhaustingthe pressurized fluid pressurizes the first side of the piston relativeto the second side of the piston to move the piston and the cylinder rodassembly in a first direction toward a first fluid end; and thensupplying pressurized fluid via a second supply line into the pistonchamber on the second side of the piston; exhausting pressurized fluidvia a first return line from the piston chamber on the first side of thepiston, wherein supplying and exhausting of pressurized fluidpressurizes the second side of the piston relative to the first side ofthe piston to move the piston and the cylinder rod assembly in a seconddirection toward a second fluid end, the second direction is opposite ofthe first direction.
 16. The method of claim 15, wherein the cylinderrod assembly further comprises: a first rod coupled to the piston andextending from the first side of the piston and out of a first side of ahydraulic cylinder forming the piston chamber; and a second rod coupledto the piston and extending from the second side of the piston and outof a second side of the hydraulic cylinder.
 17. The method of claim 16,wherein the first fluid end receives an end of the first rod thatextends out of the hydraulic cylinder, and wherein the second fluid endreceives an end of the second rod that extends out of the cylinder rodassembly.
 18. The method of claim 17, wherein one or more pumps arecoupled to the first and second supply lines to supply the pressurizedfluid into the piston chamber, and wherein one or more reservoirs arecoupled to the first and second return lines to receive the pressurizedfluid from the piston chamber
 19. The method of claim 18, wherein afirst supply valve along the first supply line that, when open, suppliesthe pressurized fluid to the piston chamber on the first side of thepiston, wherein a second supply valve along the second supply line that,when open, supplies the pressurized fluid to the piston chamber on thesecond side of the piston, wherein a first return valve along the firstreturn line that, when open, returns the pressurized fluid from thepiston chamber on the first side of the piston to the one or morereservoirs, and wherein a second return valve along the second returnline that, when open, returns the pressurized fluid from the pistonchamber on the second side of the piston to the one or more reservoirs.20. The method of claim 19, wherein a controller is configured to openthe first supply valve and the second return valve while the secondsupply valve and the first return valve are closed to move the piston inthe first direction toward the first fluid end, and wherein thecontroller is further configured to open the second supply valve and thefirst return valve while the first supply valve and the second returnvalve are closed to move the piston in the second direction.
 21. A pumpsystem, comprising: a hydraulic power end comprising a hydrauliccylinder having a hydraulic cylinder housing, and a cylinder rodassembly disposed at least partially in the hydraulic cylinder housing,the cylinder rod assembly comprising: a piston disposed in the hydrauliccylinder housing, and a rod section coupled to the piston and extendingfrom the piston and out of a first side of the hydraulic cylinder,wherein a first end of the rod section is coupled to the piston; and afluid end comprising a fluid end block, wherein a second end of the rodsection is received in the fluid end block.